"Russia’s doubling down on the murderous Assad regime is yet another example of how this administration’s feckless foreign policy has emboldened our adversaries and diminished our standing in the world," McCain said.
In rent days, Russia has confirmed that it is assisting the Syrian government led by President Bashar al-Assad in an effort to combat ISIL terrorists.
Following the news, Western media began reporting on Russia's alleged military buildup in Syria.
"Capitalizing on American inaction, Russia is now engaged in a dangerous military buildup in Syria, which has been supported by supply flights through Iranian and Iraqi airspace," McCain argued.
Earlier on Monday, Syria's Ambassador to Russia Riyad Haddad dismissed media reports claiming that Russian troops are fighting alongside Syrian Army.
Russia has been engaged in international efforts to solve the ongoing civil war in Syria, as well as provide humanitarian aid to the Syrian people.